Lec 1. Intro to musculoskeletal system and bone

Question 1

based on morphology, tissue are divided by 4 kinds

Answer 1

epithelial
nervous
connective
muscle

Question 2

5 types of connective tissue

Answer 2

tendon
ligament
fascia
cartilage
bone

Question 3

What is the composition of bone (4)

Answer 3

collagen
calcium phosphate
water
amorphous proteins

Question 4

What are the 3 parts of bone

Answer 4

Epiphysis - top part
metaphysis - where bone flares
diaphysis - shaft

Question 5

What do osteoblasts do

Answer 5

form new bone

Question 6

what to osteoclasts do

Answer 6

degradation of bone

Question 7

What is compact bone

Answer 7

dense cortical bone (shell)

Question 8

What is cancellous bone

Answer 8

trabecular bone (sponge)

Question 9

What is periosteum

Answer 9

highly innervated outer lining

Question 10

When a person breaks a bone what part sends the pain

Answer 10

the periosteum

Question 11

Osteoporosis affects bone how

Answer 11

the amount of bone is decreased and the structural integrity of trabecular bone is impaired. Cortical bone becomes more porous and thinner. This makes the bone weaker and more likely to fracture.

Question 12

Which type of bone is better at resisting compression

Answer 12

cortical bone

Question 13

Which type of bone does not resist tension forces well

Answer 13

cortical bone

Question 14

When a bone starts to bend which side (convex or concave) will initiate the fracture

Answer 14

Convex

Question 15

Which type of bone does not resist compression

Answer 15

cancellous bone - think of a sponge, you can squish it but it is better at tension

Question 16

At what week of embryonic development do limb buds appear

Answer 16

5th week

Question 17

At what week of embryonic development does endochondral ossification occur

Answer 17

7th week

Question 18

*At what week of embryonic development does the primary ossification and periosteum development happen

Answer 18

7th week

Question 19

What main thing happens at the 7th week of embryonic development

Answer 19

primary ossification and periosteum develop - first spot where cartilage becomes bone

Question 20

What happens to bone at birth

Answer 20

secondary center of ossification - cartilage is turning into bone

Question 21

What happens at the 6th week of embryonic development

Answer 21

• Mesenchymal cells replaced by cartilage

* Cartilaginous model

Question 22

What happens at the 6th month of embryonic development

Answer 22

• Resorption of central part of long bone results in formation of a medullary cavity

Question 23

When secondary ossification is complete, there are 2 possible sites for cartilaginous growth in long bone, which are

Answer 23

Articular cartilage

epiphyseal plate

Question 24

how does bone growth occur at the epiphyseal plate cartilage?

Answer 24

balance between

• Interstitial growth of the cartilage cells of the plate
• Calcification, death and replacement of cartilage

Question 25

how does bone grow in width

Answer 25

two methods:
1. Width by intramembranous ossification
-Appositional (adding layers) growth via osteoblasts within periosteum (cavity gets bigger too. osteoclasts dissolve away. but at the same time osteoblast all laying down more bone on the outside)
2. Simultaneously, medullary cavity becomes larger through osteoclastic resorption of bone
(cavity gets bigger too. osteoclasts dissolve away. but at the same time osteoblast all laying down more bone on the outside)

Question 26

Bones and all connective tissue response to stress. This is what we are trying to do with therex, we are trying to give the persons connective tissue enough stress. But, what would happen if you exceed the load?

Answer 26

tissue will fail

Question 27

Wolff’s law

Answer 27

remodeling of bone in response to physical stress

bone deposited in sites subjected to stress

bone resorbed from sites where there is little stress ( if you don’t use it you lose it. )

Question 28

Concave vs convex side of bone

Answer 28

cortical bone resist compression. good for concave side of the bone. without thick cortical bone this would buckle. but cortical not good for tension. the more lateral side will have more tension. and the lateral side has thin cortical bone.

Question 29

Concave bone properties

Answer 29

Thick Cortical bone

Better Alignment of trabecular systems

Question 30

Convex bone properties

Answer 30

Thin Cortical bone

Decreased Alignment of trabecular systems

Question 31

Theory of induced electrical potentials

Answer 31

Negative electrical charge on concave side of bone
–>Compression force = deposition

Positive electrical charge on convex side of bone
–>Tension force = resoption

Question 32

What are the clinical implications for the theory of induced electrical potentials

Answer 32

Electrical stimulation of osteogenesis when there is delayed union of fracture

bone stimulator - is a device that a person will wear that will help stimulate growth

Question 33

A person with what condition would you not want to stimulate bone growth

Answer 33

myositis ossificans - you do not want to stimulate bone growth in a muscle or any type of heterotopic ossification